1. Field of the Invention
This invention relates to a mounting structure for mounting an auxiliary machinery of an engine to an engine body.
2. Description of the Related Art
There is a typical structure in which a timing belt is rotatably provided along an end surface of a cylinder block of a four-cycle engine to transmit power to a valve driving mechanism and a timing belt cover is fixed to the end surface of the cylinder block so as to cover the timing belt.
FIG. 12 is an example disclosed in Japanese Patent Laid-Open Publication No. hei 8-28231, in which an oil pump body 03 is partially fixed to an end surface of a cylinder block 01 (end surface vertical to the crank shaft), and a cover 03 extends from the cylinder block 01 to the cylinder head to cover the timing belt. The cover 03 covers a part of the oil pump body 02.
Therefore, a hydraulic control valve 04 as an auxiliary machinery is mounted on a seat surface formed on the oil pump body 02 not interfering with the cover 03 so as to minimize the entire length of the engine in the lengthwise direction of the crank shaft.
However, because the hydraulic control valve 04 results in being mounted to the cylinder block 01 via the oil pump body 02, the entire length of the engine remains large by the amount corresponding to the width of the oil pump body 02.
To ensure rigidity of mount seat for mounting the hydraulic control valve 04, the oil pump body 02 is required to be thick, and this further increases the entire length of the engine.
It is therefore difficult to ensure a sufficient rigidity of the cover seal surface for engaging the cover 03 located near the mount seat of the oil pump body 02 difficult to be sufficiently rigid.
Additionally, if an auxiliary machinery is mounted through a bracket, it increases the number of parts and invites a decrease of the mounting rigidity of the auxiliary machinery.
Under those circumstances, it is an object of the present invention to provide an auxiliary machinery mounting structure of an engine capable of reducing the entire length of the engine, enhancing the rigidity of the cover seal surface thereby to improve the sealing efficiency and also improving the mounting rigidity of the auxiliary machinery.
In addition, in case a power unit incorporating an engine and a transmission is tried to be mounted to a vehicle body from the bottom of the vehicle body by lifting the power unit through between a pair of frames, the distance of the pair of frames in a conventional structure had to be larger than the size of the power unit itself plus the size of the mount bracket. Therefore, largely spaced frames have been inevitably made and the power unit was mounted thereon, and it has been regarded inevitable that the vehicle width increases. Furthermore, in case the power unit is mounted to a compact vehicle body having narrow-spaced frames, another method has been employed, which mounts the power unit by lowering it from above the frame. This method, however, involves the disadvantage that the process of mounting the power unit requires man-hour.
It is therefore a further object of the invention to provide a mount device having a mount bracket that permits an engine/transmission-incorporated power unit to be mounted to a vehicle body having a pair of frames spaced by a distance narrower than the size of the power unit itself plus the dimension required for the mount bracket by lifting the power unit from the bottom side, thereby to enable downsizing of vehicles.
According to the present invention, there is provided an auxiliary machinery mounting structure of and engine comprising a mount seat for an auxiliary machinery, the mount seat being integrally formed on an end surface of a cylinder block extending vertically to a crank shaft of the engine to lie outward of and along a cover seal surface which is a surface engaging with a cover laid over the end surface, and an auxiliary machinery being mounted on the mount seat.
According to the present invention, because a mount seat with a sufficient thickness can be formed on an end surface of the cylinder block without increasing its thickness, and an auxiliary machinery can be attached directly to the mount seat, entire length of the engine including that of the auxiliary machinery can be reduced.
In addition, because the mount seat is formed in the cylinder block, it has a high rigidity, and the cover seal surface formed along the mount seat is also ensured to have a high rigidity, thereby to improve the sealing effect in combination of the cover and improve the mounting rigidity of the auxiliary machinery.
In the auxiliary machinery mounting structure of the engine, the mount seat is preferably formed to thrust into a blow-by gas path formed in the cylinder block.
With this arrangement, because the mount seat thrusts into the blow-by gas path, the passage area of the blow-by gas path partly changes, and it is expected that separation of blow-by gas to air and liquid is promoted. At the same time, since the mount seat extends into the blow-by gas path, it contributes to downsizing the engine.
Still in the auxiliary machinery mounting structure of the engine, the auxiliary machinery may be an auto tensioner.
In this configuration, since the auto tensioner can be attached to the high-rigidity mount seat formed on the end surface of the cylinder block, the auto tensioner normally loaded with a counter force to the biasing force can be fixed firmly.
The auxiliary machinery mounting structure of the engine may be configured to mount the auxiliary machinery directly to the mount seat formed in the cylinder block.
With this configuration, since the auxiliary machinery can be mounted directly to the mount seat formed in the cylinder block, easy and firm attachment of the auxiliary machinery in the engine is ensured.
In the auxiliary machinery mounting structure of the engine, the engine may be of a V-bank type in which a plurality of cylinders are offset from each other in the crank shaft lengthwise direction, and the auxiliary machinery may be located in a space made by the offset arrangement of the cylinders.
With this arrangement, the entire length of the engine including that of the auxiliary machinery can be reduced in the crank shaft lengthwise direction.
Still in the auxiliary machinery mounting structure of the engine, the engine may be of a V-bank type in which a plurality of cylinders are offset from each other in the crank shaft lengthwise direction, and the blow-by gas path of the cylinder block may be formed in a space made by the offset arrangement of the cylinders.
With this arrangement, since the mount seat is formed to thrust into the blow-by gas path formed in the space made by the offset arrangement, the engine itself is effectively downsized, and a partial change of the path area of the blow-by gas path effectively promotes separation of the blow-by gas to air and liquid.
According to the invention, there is further provided a power unit mounting device used at a portion where a power unit is suspended to one of vehicle frames when mounted by lifting it from below and through the vehicle frames, characterized in that a mount bracket to be attached to the power unit is composed of a stump portion having a short size and an extension to be connected to make up the full length required for the mount bracket.
With this configuration, upon mounting the power by raising it from below and between the vehicle frames, when the device is attached only at its short stump portion and raised, since the gap between the frame and the power unit is large, the power unit can be mounted easily, and the workability can be improved.
The extension of the mount bracket may be mounted at a position overlapping the vehicle frames when viewed from above.
With this configuration, even when the pair of frames have a gap too narrow for a power plant having mounted a mount bracket with a full size to pass through from below to above, the power unit having mounted only the stump portion of the short mount bracket can pass through from below to above. The extended portion can be attached after the power unit passes through to form the integral mount bracket with the full size, and this can be provided for mounting the power plant. Since it enables the mounting of the power plant by lifting it even in a vehicle having narrow-spaced frames, the invention contributes to downsizing the vehicle body.
An end surface of a cylinder block vertical to a crank shaft of an engine, which forms a part of the power unit, may be oriented substantially in parallel to the frames, and a mount seat for an auxiliary machinery may be integrally formed at a position along the cover seal surface outside the cover seal surface for engaging with the cover laid over the end surface of the cylinder block, such that the auxiliary machinery can be mounted on the mount seat and the mount bracket is attached to the end surface of the cylinder block.
With this configuration, the auxiliary machinery is mounted on the mount seat along the end surface of the cylinder block substantially in parallel to the vehicle frames, and the mount bracket is attached to the end surface of the cylinder block. As a result, even after the auxiliary machinery is attached to the cylinder block, the power unit can be easily mounted to the vehicle frames.
An end surface of the cylinder block vertical to the crank shaft of the engine, which forms a part of the power unit, may be oriented substantially in parallel to the frames, and the mount seat for the auxiliary machinery may be integrally formed at a position along the cover seal surface outside the cover seal surface for engaging with the cover laid over the end surface of the cylinder block, such that the auxiliary machinery can be mounted on the mount seat and the mount seat thrusts into the blow-by gas path formed in the cylinder block.
With this configuration, in the mount device capable of easily mounting the power unit to the vehicle frames, the engine having a blow-by gas path exhibiting a high effect of separating blow-by gas to air and liquid can be decreased in size.
The engine forming a part of the power unit may be of a V-bank type in which a plurality of cylinders are offset from each other in the crank shaft lengthwise direction, an end surface of the cylinder block vertical to the crank shaft may be oriented substantially in parallel with the frames, the mount bracket may be attached to the end surface of the cylinder block, and the auxiliary machinery may be located in a space made by the offset arrangement of the cylinders.
With this configuration, the auxiliary machinery can be located on the end surface of the cylinder block of the engine so that it does not project externally from the end surface, and the power unit can be mounted to the vehicle frames more easily and reliably.
The engine forming a part of the power unit may be of a V-bank type in which a plurality of cylinders are offset from each other in the crank shaft lengthwise direction, an end surface of the cylinder block vertical to the crank shaft may be oriented substantially in parallel with the frames, the mount bracket may be attached to the end surface of the cylinder block, and the auxiliary machinery may be located on the mount seat positioned in a space made in the cylinder block by the offset arrangement of the cylinders.
With this configuration, on one end surface of the cylinder block of the engine, the mount seat can be formed in a space made in the cylinder block by the offset arrangement of the cylinders, and upon mounting the power unit to the vehicle frames, the auxiliary machinery can be mounted on the mount seat so that it does not project from the end surface of the cylinder block. As a result, the power unit can be mounted to the vehicle frames more smoothly.
Furthermore, the engine forming a part of the power unit may be of a V-bank type in which a plurality of cylinders are offset from each other in the crank shaft lengthwise direction, an end surface of the cylinder block vertical to the crank shaft may be oriented substantially in parallel with the frames, the mount bracket may be attached to the end surface of the cylinder block, and the mount seat may be formed to thrust into the blow-by gas path formed in a space made in the cylinder block by the offset arrangement of the cylinders, and the auxiliary machinery may be mounted on the mount seat.
With this configuration, both the blow-by gas path having a high effect of separating air and liquid and the auxiliary machinery mount seat can be formed on the end surface of the cylinder block, and the auxiliary machinery can be attached to the auxiliary machinery mounting seat.